Neuroendocrine Tumors

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in Targeted Radiopharmaceuticals

RYZ101 for gastroenteropancreatic neuroendocrine tumors, or GEP-NETS

Gastroenteropancreatic neuroendocrine tumors, or GEP-NETs, are rare tumors with an incidence of approximately 18,000 patients annually in the United States(1). The prognosis for patients with GEP-NETs depends on tumor grade and other histopathologic characteristics. Approximately 80% of GEP-NETs express the somatostatin receptor type 2 (SSTR2). Radiopharmaceutical Therapy (RPT) comprising a somatostatin analog peptide labeled with the beta-emitting radioisotope lutetium-177 (Lu177), has shown significant clinical benefit and is approved for treatment of adult patients with SSTR+ GEP-NETs in Europe and the United States.

While initial clinical treatment with Lu177-based therapies is promising, nearly all patients eventually experience tumor progression and have limited subsequent treatment options. RYZ101 is an investigational, targeted RPT designed to deliver a highly potent alpha-emitting radioisotope, Actinium-225 (Ac225), to solid tumors expressing SSTR2. RYZ101 is being evaluated for safety and PK in a Phase 1b trial in patients with inoperable, advanced, well-differentiated, SSTR+ GEP-NETs that have progressed following treatment with Lu177-labelled somatostatin analogue therapies, such as Lutathera.

Following completion of our ongoing Phase 1b trial, we intend to initiate a Phase 3 registrational trial to assess efficacy and safety of RYZ101 compared against investigator-selected standard of care therapy in a similar patient population.

RYZ101 has the potential to be the first approved Ac225 RPT and could address the much needed treatment gap for patients with GEP-NETs who progress following Lu177-based therapies.

RYZ101 leverages DOTATATE, a known binder and linker used in other radiopharmaceutical produts. RYZ101 uses Ac225 instead of the Lu177 used in Lutathera and thus delivers hundreds of times more potency in cancer cell killing. The higher potency of RYZ101 can provide significant clinical benefit to patients. RYZ101 utilizes a proprietary and patent protected formulation.

Structure of RYZ101
Structure of RYZ101

Details of the study can be found on

(1): Xu 2021